[macppc] Unbreak mail/hashcash

Hi,

> http://build-failures.rhaalovely.net/powerpc/2020-04-09/mail/hashcash.log

Because clang defines __POWERPC__ while gcc does not, it's assumed
we're Mac OS [0]. Reverting to the gcc behaviour allows hashcash to
be built once again.

I did not bump REVISION because it has never been built since the clang
switch.

Comments/feedback are welcome,

Charlène.


[0] https://en.wikipedia.org/wiki/Gestalt_(Mac_OS)


Index: patches/patch-libfastmint_c
===================================================================
RCS file: patches/patch-libfastmint_c
diff -N patches/patch-libfastmint_c
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-libfastmint_c 1 May 2020 22:00:35 -0000
@@ -0,0 +1,16 @@
+$OpenBSD$
+
+OpenBSD/macppc is not Mac OS, we don't ship Gestalt.
+
+Index: libfastmint.c
+--- libfastmint.c.orig
++++ libfastmint.c
+@@ -6,7 +6,7 @@
+ #include <CoreServices/CoreServices.h>
+